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Date: Tue, 9 Apr 2024 16:59:02 +0200
From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Oleg Nesterov <oleg@redhat.com>, linux-mips@vger.kernel.org,
	linux-kernel@vger.kernel.org, Xi Ruoyao <xry111@xry111.site>
Subject: Re: [PATCH] MIPS: scall: Save thread_info.syscall unconditionally on
 entry
Message-ID: <ZhVXtv7CX7CGm3R6@alpha.franken.de>
References: <20240328-mips_save_syscall-v1-1-9e1d62d6999d@flygoat.com>
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In-Reply-To: <20240328-mips_save_syscall-v1-1-9e1d62d6999d@flygoat.com>

On Thu, Mar 28, 2024 at 02:27:56PM +0000, Jiaxun Yang wrote:
> thread_info.syscall is used by syscall_get_nr to supply syscall nr
> over a thread stack frame.
> 
> Previously, thread_info.syscall is only saved at syscall_trace_enter
> when syscall tracing is enabled. However rest of the kernel code do
> expect syscall_get_nr to be available without syscall tracing. The
> previous design breaks collect_syscall.
> 
> Move saving process to syscall entry to fix it.
> 
> Reported-by: Xi Ruoyao <xry111@xry111.site>
> Link: https://github.com/util-linux/util-linux/issues/2867
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/include/asm/ptrace.h |  2 +-
>  arch/mips/kernel/asm-offsets.c |  1 +
>  arch/mips/kernel/ptrace.c      | 15 ++++++---------
>  arch/mips/kernel/scall32-o32.S | 23 +++++++++++++----------
>  arch/mips/kernel/scall64-n32.S |  3 ++-
>  arch/mips/kernel/scall64-n64.S |  3 ++-
>  arch/mips/kernel/scall64-o32.S | 33 +++++++++++++++++----------------
>  7 files changed, 42 insertions(+), 38 deletions(-)

applied to mips-fixes.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]